Nozzle for a bottom pour ladle for molten metal



United States Patent 3,395,840 NOZZLE FOR A BOTTOM POUR LADLE FOR MOLTEN METAL Weldon J. Gardner, Greentree Borough, Pa., assignor to Vesuvius Crucible Company, Swissvale, Pa., a corporation of Pennsylvania Filed July 15, 1966, Ser. No. 565,522 4 Claims. (Cl. 222566) ABSTRACT OF THE DISCLOSURE A nozzle for a bottom pour ladle for molten metal comprising a sheath with a separate core in the lower portion of the sheath and a separate seat shaped to receive and cooperate with a ladle stopper to close the nozzle in the upper portion of the sheath above the core. Interfitting means may be provided between the seat and sheath positively holding down the seat relatively to the sheath preventing lifting of the seat from the sheath due to the tendency of the seat to adhere to the ladle stopper when the stopper is lifted. The interfitting means .may be screw threads. The inside of the sheath and the outside of the core may be equally tapered downwardly and inwardly whereby the core is seated and retained in the sheath. The core may be threaded into the sheath. The sheath may be of insulating refractory material, the core of wear resistant refractory material and the seat of pyroplastic refractory material.

This invention relates to a nozzle for a bottom pour ladle for molten metal and particularly to a multipart nozzle having elements adapted to be assembled to form the nozzle and which may be replaced by other elements of the same shape but of different metallurgical characteristics so that the nozzle may be adapted to the particular molten metal being delivered or teemed from the ladle through the nozzle.

My nozzle is especially adapted for use in a ladle for teeming molten metal, such as molten steel, into ingot molds. Different steels have different characteristics affecting the action of the molten steel on the nozzle. Some steels are relatively caustic and tend to chemically attack the nozzle while other steels have a more pronounced abrasive effect. It is desirable to be able to adapt the nozzle to most effectively resist the deteriorating effect, chemical or physical, of the steel or other molten metal flowing through the nozzle.

My nozzle comprises a sheath with a separate core in the lower portion of the sheath and a separate seat in the upper portion of the sheath above the core. The core shapes the stream of molten metal issuing from the nozzle. The seat is the element of the nozzle against which the ladle stopper acts to shut off the flow, as when the ladle is to be moved from one ingot mold to another.

The nozzle sheath is mounted in the ladle with the core disposed in the lower portion of the sheath and the seat above the core. The nozzle elements may be assembled before the nozzle is applied to the ladle or the nozzle sheath may be mounted in the ladle and the core and seat then applied.

I desirably provide interfitting means between the seat and the sheath positively holding down the seat relatively to the sheath preventing lifting of the seat from the sheath due to the tendency of the seat to adhere to the ladle stopper when the stopper is lifted. In my preferred form of nozzle the interfitting means are screw threads.

The inside of the sheath and the outside of the core may be equally tapered downwardly and inwardly whereby the core may be seated and retained in the sheath. Then application of the seat atop the core completes the "ice nozzle assembly, the interfitting means acting between the seat and sheath holding the nozzle elements together.

The inside of the sheath and the outside of the core may be threaded so that the core is maintained in place in the sheath by the interfitting threads similarly to the action of the threads of the seat and sheath.

The sheath is of insulating refractory material, normally fire clay. Other insulating refractory materials may be substituted, such, for example, as bubbled alumina or other known equivalent porous refractory material having insulating properties due to its porosity.

The core is of relatively wear-resistant refractory material. Examples of such materials are magnesium oxide, mullite, high alumina clay-graphite and zircon.

The seat is desirably of pyroplastic refractory material. I may make the seat of -95% (preferably zircon with the remainder zirconium oxide. Alternatively the seat may be made of zircon and alumina or zircon and refractory clay, or under particular circumstances the materials above specified for the core may be used for the seat.

The advantage of using pyroplastic material for the seat is that the seat is thereby adapted to plastically yield to some extent under the pressure of the ladle stopper at operating temperature and upon raising of the ladle stopper partially restores itself, this characteristic persisting through repeated closing and opening of the nozzle.

Other details, objects and advantages of the invention will become apparent as the following description of certain present preferred embodiments thereof proceeds.

In the accompanying drawings I have shown certain present preferred embodiments of the invention in which:

FIGURE 1 is a fragmentary cross-sectional view of a refractory-lined steel ladle for teeming molten metal with one form of my multipart nozzle mounted therein; and

FIGURE 2 is a cross-sectional view of another form of my multipart nozzle.

Referring now more particularly to the drawings and first to FIGURE 1, the ladle except for the nozzle may be of conventional shape and therefore only the portion thereof in which the nozzle is mounted is shown. The ladle shell 2 is made of steel and the ladle is lined with refractory material 3 as well known to those skilled in the art. The shell 2 has an opening 4 to receive the lower portion of the nozzle, and a nozzle supporting ring 5 is bolted to the shell by bolts 6. Disposed in the ladle above the opening 4 is a nozzle mounting block 7 of refractory material; this may be either a preformed block or refractory material rammed in place. A ladle stopper which may be of conventional shape is employed as diagrammatically illustrated at 8.

All of the structure above described may be conventional.

The multipart nozzle is mounted in the block 7 and comprises a sheath 9, a core 10 and a seat 11. These three elements are separately formed and may be and preferably are of different materials as above explained and are adapted to be assembled to form the nozzle either before the nozzle is mounted in the block 7 or by mounting the sheath in the block and then applying the core and seat.

The sheath 9 serves to properly position the core and seat. In the structure shown in FIGURE 1 the inner surface of the sheath is smoothly tapered downwardly and inwardly in the form of a portion of the surface of a cone. The outer surface of the core 10 is similarly shaped so that when the core is dropped into the sheath the core will be properly positioned and maintained against falling out through the bottom of the sheath by the taper as shown in FIGURE 1. The sheath may be similarly retained in the block 7 or the supporting ring may be relied upon to hold the nozzle in the ladle.

After the core has been inserted into the sheath, either before or after the sheath is mounted in the block 7, the seat 11 is screwed into the upper portion of the sheath atop the core whereby the integrity of the nozzle is insured. The threading of the seat into the upper portion of the sheath prevents lifting of the seat with the ladle stopper 8 if the seat tends to adhere to the ladle stopper.

FIGURE 2 shows a modified form of my multipart nozzle which may be substituted for the form of nozzle shown in FIGURE 1. In the form of FIGURE 2 the core 10a is mounted in the sheath 90 by being threaded thereinto similarly to the threading of the seat into the upper portion of the sheath. In FIGURE 2 the seat 11a may be identical to the seat 11 of FIGURE 1.

In either form the bore through the core may be either cylindrical or tapered in the form of a portion of the surface of a cone or otherwise shaped, depending upon the characteristics of the stream of molten metal issuing from the nozzle which may be desired.

As above indicated, the elements of the nozzle may be selected for optimum resistance to the molten steel or other molten metal being poured. Insulation of the seat by a sheath of insulating refractory material reduces skulling and consequent inclusions. A core of wear resistant refractory material and a seat of pyroplastic refractory material further reduce the likelihood of inclusions and leakage. Control of the pouring rate is provided for, the seat being shaped to accommodate either a conical or a spherically shaped stopper head. When a conical stopper head is employed a throttling or needle valve action is provided for. The flow can be maintained reasonably uniform during pouring, without dependence upon bore erosion.

While I have shown and described certain present preferred embodiments of the invention it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied within the scope of the following claims.

I claim:

1. A nozzle for a bottom pour ladle for molten metal comprising a sheath with a separate core in the lower portion of the sheath and a separate seat shaped to receive and cooperate with a ladle stopper to close the nozzle in the upper portion of the sheath above the core, the nozzle including interfitting means between the seat and sheath positively holding down the seat relatively to the sheath preventing lifting of the seat from the sheath due to the tendency of the seat to adhere to the ladle stopper when the stopper is lifted, the interfitting means being screw threads.

2. A nozzle for a bottom pour ladle for molten metal comprising a sheath with a separate core in the lower portion of the sheath and a separate seat shaped to receive and cooperate with a ladle stopper to close the nozzle in the upper portion of the sheath above the core, the core being threaded into the sheath.

3. A nozzle as claimed in claim 1 in which the core is threaded into the sheath.

4. A nozzle as claimed in claim 3 in which the sheath is of insulating refractory material, the core is of wear resistant refractory material and the seat is of pyroplastic refractory material.

References Cited UNITED STATES PATENTS 1,072,872 9/1913 Michaels 222-567 1,635,839 7/1927 Hassall et al. 222566 X FOREIGN PATENTS 337,754 10/ 1934 Netherlands. 228,418 7/1963 Austria.

STANLEY H. TOLLBERG, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,395 ,840 August 6 1968 Weldon J. Gardner It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 31, "1,072,872" should read 1,072,972 line 35 "337 ,754" should read 33 ,754

Signed and sealed this 23rd day of December 1969.

(SEAL) Attest:

Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer WILLIAM E. SCHUYLER, IR. 

